Sectional filter for exhaust filtration.



No.' 884,797.l

. RATRNTRD ARR. I4, 190s.

IIJRGRUSH. K SRGTIONAL TILTRR PoR EXHAUST FILTRATION.

APPLICATION FILED DEG. 17, '1906.

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UNITED STATES PATENT OFFICE.

HUGO PHILIP CRUSH, OF CHARLTON, ENGLAND, ASSIGNOR TO ALFRED J AMES, OFLONDON,

ENGLAND.

SECTIONAL FILTER FOR EXHAUST FILTRATION.

To all whom it may concern:

Be it known that I, HUGO PHILIP CRUSH, a subject of the King of GreatBritain, residing at Charlton, in the county of Kent, England, haveinvented Improvements in Sectional Filters for Exhaust Filtration, ofwhich the following is a specification.

The object of this invention is to facilitate the de-watering or thewashing of ore slime, precipitate and other material by the provision ofa rigid self-cleaning or emptying lter-frame worked by the applicationof a vacuum as herein described. In other proposed methods of vacuum orexhaust filtration the filter-frame is cleaned by hand or by a flow ofwater or a reverse current of air or water, all of which are expensive.

This invention 'provides a frame which from its construction and methodof working is self-emptying and requires no back pressure of air orwater.

The invention is illustrated in the accompanying drawing, in whichFigure 1 is a side view of one of the filterframes mainly in section,Fig. 2 a cross section thereof drawn to a larger scale, and Fig. 3 adetailed view of part of the filter-frame drawn to a still larger scale.y

I make a frame of great rigidity and of great superficies and yet of butlittle weight by building together sheets of pressed metal such as iron,or aluminium when suitable,-

such metal being pressed into ridges or channels similar to corrugatedgalvanized iron, but with the difference that the corrugations or ridgesare sharp or angular and not rounded, so as to present support but notsurface to the filtering material placed on them. Such ridges may be oneinch or any other convenient distance between the centers.

The sheets, which may be of iron 1 50th 'of an inch thick or otherconvenient size, and which may be protected from the action of thesolution by special paint, galvanizing or other suitable means, areattached to each other by rivets at say 4 from the bottom of each sheetuntil they form a plate 1 of the required size, say 14 ft. by 14 ft.This plate 1 is supported in a rectangular frame composed of a pipe 2,of 1%,- inch diameter or other suitable size, which runs along the endsand bottom of said plate and a top bar 3, which Specification of'Letters Patent.

Application filed December 17, 1906.

Patented April 14, 1,908.

Serial No. 348,324.

runs along the top thereof, the upper ends of said pipe extendingthrough said top bar.

The pipe 2 is slotted along its top at the bottom of the frame so as toreceive the corrugated plates 1, the slots being linterrupted for every18 or other convenient distance, as shown at 4, to serve as a support tothe sides of the pipe. The top of the corrugated plate 1 is let into thetop bar 3, and wires 5 which may be 6 long by 5 thickness are fixed atan angle from the wood block and the plate so as to prevent thefiltering material 6 being drawn into the corner formed by the junctionof the wood and corrugated metal sheet. These wires constitute spreadersfor the cloth or filtering fabric and facilitate the self-cleaning oremptying action of the plate. I prefer that these wires should be fixedwith a slightly convex curve as shown in Fig. 2, as it will be foundthat after the plate has received a suitable charge, determined byexperiment for each type of material, so soon as the application of thevacuum ceases the cloth and material will fall away from the junction ofthe wire to the vertical sheet of the frame, and this falling awaycauses a rolling or falling action to start on the material on theframe, which thus empties itself.

The corrugated sheet 1 is fixed within the frame composed of the blockor rail 3 on top and the tubes 2 along the ends and bottom by bolt 7 ofiron or other suitable material placed alternately each side of the ironsheet (four bolts would suffice for the size sheet above mentioned) thelower ends of the bolts are riveted flush into the bottom tube thuspresenting a smooth surface for the filtering material.

Along the four vertical sides of the rail 3 which is preferably composedof wood is chased a groove 8 which may be 32 wide and deep to permit ofthe calking in of the edges of a bag of suitable filtering fabric, sewedto shape, in which the frame constructed as before described is placed;the edges of the bag are calked with twine, thin rope, or other suitablematerial, and on each of the four vertical sides of the rail 3 isscrewed a suitable piece of timber 9 of similar surface dimensions andsay 1 thick, which keeps tight the oint of the top of the bag with thewooden rail. Provision is also made for the escape of air when immersingthe frame, by inserting a piece of pipe 10 through the frame to near thesurface of the corrugated plate;

' this air escape tube is connected by hose 11 or other suitable meansto the escape air pipe system 12 as described below.

To the top of the wooden rail at suitable places are fixed two sets ofbolts 13 each with a top plate 14 by means of which the frame can beswung on the two joists 15 forming the main support of the group offrames termed a basket. A suitable number of these filters or frameshaving the filtering bags or fabric thereon, which may be for instancetwelve, are swung on to two suitable joists, which may for example besteel j oists of 8 by 3 section, at suitable intervals or distances, say12, apart, so that the frames may be in parallel at intervals sufficientto allow the cakes to fall off readily.

The two j oists 15 each carry a main pipe to one (16) of which thesuction pipe 2 of each plate is connected by hose 17 or other suitablemeans, and it is convenient to have gage glasses 18 connected at eachpoint so that the precise working of each frame may be ascertained andkept under observation; to the other main pipe 12 the air escapeattachment is made from each frame, and this main has a cock by whichconnection with the atmosphere can be made or cut off. The vacuum main16 is connected to the vacuum pump system by means of flexible hose orother suitable means. The two joists 15 are also provided with fourrings or hooks 19 one at the end of each joist, by means of which thewhole set of frames or basket may be swung and raised or lowered orsuspended at will.

The method of working is to immerse the basket filter into a suitabletank containing, in sus ension, the material to be filtered, ordehydiated; such a tank may for instance be one foot larger each waythan the basket frame and may be provided with guides on opposite sidesof the upper edge of the tank to direct its basket as it is lowered andto kee it in position.

suspension by suitable known means. The pipes may be convenientlyjointed to facilitateremoval in the event of any clicking occurring.

As the basket is being lowered into the agitated pulp, the escape aircocks are opened until the basket is in position and air ceases toescape; the escape cocks are now turned off and the vacuum turned on.The behavior of each frame and the amount of solution and of air beingdrawn through may be readily ascertained by glancing at the gage glassindications after a suitable interval to be determined by experiment;thus a very e material to be filtered may be kept in clayey slimecontaining but little fine sand perceptible to the touch takes 115minutes with a vacuum of 25 inches to form a suitable cake l to 1%inches thick; the basket is lifted with the vacuum still on and plungedinto a similar tank containing water or other washing fluid if thematerial is to be washed instead of dehydrated) and the water or otherfluid is sucked through for a sufficient time-in the above instance from30 to 40 minutes. The basket is then again lifted with the vacuum stillon and hoisted to the discharging trough. So soon as cracks appear onthe surface of the dehydrated material the vacuum is turned off and theair escape cocks turned on the cloth 6, released from the effect of thevacuum, bellies, and the cakes if properly made fall off with a rollingmotion. 1f necessary the falling off of the cakes can be assisted by aman with a stick. The edges of the framing are wiped down and the basketis now ready for a fresh charge.

What 1 claim, and desire to secure by Letters Patent, is

1. A filter section comprising a light rigid filter frame composed of athin ridged metal plate and a marginal frame consisting of a top bar anda tube adapted for connection with a vacuum apparatus, said tubeextending along the ends and bottom of said plate and being providedwith an exhaust opening, and a filter bag disposed on said frame andcalked into the top bar thereof.

2. A filter section comprising a light rigid filter frame composed of athin ridged metal plate and a marginal frame consisting of a top bar anda tube adapted for connection with a vacuum apparatus, said tubeextending along the ends and bottom of said plate and being providedwith an exhaust opening, and a filter bag disposed on said frame andinclined spreaders de endent from said top bar on opposite side ofsaidplate tofacilitate on the stoppage of the exhaust automatic breakingaway of the cake formed on the filter fabric during the application of avacuum.

3. A filter frame adapted for carrying a filtering fabric on oppositesides for exhaust filtration, comprising a sheetmetal plate havingangular ridges, a marginal frame therefor and spreaders extendingdownward from the top bar of said frame on opposite sides of said platefor spreading the filter fabric near the top.

4. A filter frame adapted to carry a filtering fabric on opposite sidesfor exhaust filtration, comprising a corrugated sheet metal plate and amarginal frame therefor, the bottom of said frame being a slottedexhaust pipe and said corrugated plate extending into the slot thereof.

5. A lter frame adapted to carry a lterf In testimony whereof I havesigned my ing fabric on its opposite Sides for exhaust iilname to thisspecification in the presence of tration7 comprising asheet metal platehav two subscribing Witnesses.

ing angulal` corrugations and a marginal HUGO 'PHILIP CRUSH. frametherefor, the bottom of said frame be- Witnesses: ing a slotted exhaustpipe and said eorru- JOHN W. LLOYD-JONES,

gated plate extending into the slot thereof. STANLEY S. HAWKINS. f

